Tumbling machine with automatic discharge

ABSTRACT

A VESSEL WITH AN ANNULAR TREATMENT CHAMBER, RESILIENTLY AND NONROTATABLY SUPPORTED ON A PLATFORM, IS SET IN WOBBLING MOTION BY A REVERSIBLY ROTATABLE, ECFENTRICALLY WEIGHT CENTRAL SHAFT WHEREBY A MASS OF MOBILE PARTS IN THE CHAMBER IS AGIATED TO CIRCULATE ALONG THE CIRCUMFERENCE OF THE VESSEL IN A DIRECTION CONFORMING TO THE SENSE OF SHAFT ROTATION. AN OUTLET PORT, DISPOSED TANGENTIALLY IN A WALL OF THE TREATMENT CHAMBER. LEADS TO A DISCHARGE DUCT WHICH RECEIVES THE TREATED PARTS ONLY WHEN THE SENSE OF ROTATION IS IN THE DIRECTION OF DIVERGENCE OF THE OUTLET PORT FROM THE TREATMENT CHAMBER, THE DISCHARGE DUCT MAY INCLUDE A SCREENING SECTION FOR THE SEPRATION OF LARGER AND SMALLER PARTS, WITH RETURN ON EITHER FRACTON TO THE TREATMENT CHAMBER.

Nov. 9., 1971 E- HUBER E-TAL 3,618,261

TUMBLING MACHINE WITH AUTOMATIC DISCHARGE Filed April 14, 1970 3 Sheets-Sheet 1 Ernst Huber \28 Simon Jacof X [NV/5N! ()RS'.

K r To Attorney Nov. 9, 1971 HUBER ETAL 3,618,267

TUMBLING MACHINE WITH AUTOMATIC DISCHARGE Filed April 14, 1970 3 Sheets-Sheet z mmmmmm Ernsf Huber Simon Jacof INVI'JN'I'URS'.

Attorney Nov. 9, 1971 HUBER ETIAL TUMBLING MACHINE WITH AUTOMATIC DISCHARGE 3 Sheets-Sheet 5 Filed April 14, 1970 Ernsf Huber Simon Jacof INVI'JN'I'URS'.

5 M g (Riv Attorney United States Patent U.S. Cl. 51163 9 Claims ABSTRACT OF THE DISCLOSURE A vessel with an annular treatment chamber, resiliently and nonrotatably supported on a platform, is set in wobbling motion by a reversibly rotatable, eccentrically weighted central shaft whereby a mass of mobile parts in the chamber is agitated to circulate along the circumference of the vessel in a direction conforming to the sense of shaft rotation. An outlet port, disposed tangentially in a wall of the treatment chamber, leads to a discharge duct which receives the treated parts only when the sense of rotation is in the direction of divergence of the outlet port from the treatment chamber; the discharge duct may include a screening section for the separation of larger and smaller parts, with return of either fraction to the treatment chamber.

Our present invention relates to a tumbling machine with one or more vessels designed for the agitation of relatively mobile turnings and other articles to be polished, deburred, coated or similarly treated. In such machines it is usually necessary to arrest the driving mechanism for the vessel when the same is to be unloaded or when a part of the charge is to be removed, e.g. for the replacement of a spent solid granular treatment agent with some other additive. Prior devices designed for the automatic emptying of rotating or wobbling tumblers have been cumbersome and unreliable.

The general object of our invention, therefore, is to provide simple and dependable means in such a machine for automatically discharging a load of relatively moving parts therefrom.

A more specific object is to provide means in such a machine for separating the charge into different fractions and removing one fraction from the treatment vessel while returning another fraction to that vessel whereby, for example, a mass of abrasive chips serving for the grinding and polishing of larger parts may be reused with a different load.

A particularly advantageous type of tumbling vessel has an annular treatment chamber in which the charge is circulated while undergoing a helicoidal motion in a closed toroidal path, the vessel being resiliently supported and held against rotation while being mechanically linked with a rotating impeller. Such an impeller may have the form of a generally upright shaft driven from a motor via two cascaded universal joints, this shaft thus having two degrees of freedom so as to be able to exert separate thrust on two levels upon the vessel by way of a lower and an upper bearing. These thrusts are generated by a pair of eccentric weights respectively positioned near these bearings, with the upper weight leading the lower weight by about 90 in the direction of rotation so that the wobbling vessel is tilted in that direction whereby the charge experiences a corresponding precession.

In a copending application filed by one of use, Ernst Huber, there has been disclosed and claimed a mounting of one of the weights on the impeller member by a lostmotion coupling allowing this weight swing through an arc of when the sense of rotation is reversed, thereby letting the upper weight invariably lead the lower weight regardless of the direction of motion. This system, therefore, constitutes a reversible wobble drive adapted to generate the aforedescribed helicoidal motion of the charge, with a precession in one direction or the other along the periphery of the annular treatment chamber. Because of the three-dimensional character of this motion, the parts are thoroughly mixed and agitated for effective tumbling action.

We have found, in accordance with the present invention, that a mass of mobile parts present in such a vessel can be indefinitely recirculated for treatment even if this vessel is provided, at the bottom or a lateral wall of the chamber, with an outlet port diverging substantially tangentially from the chamber, as long as the sense of precession is in the direction of convergence of the outlet port with the chamber; if the impeller rotation and therefore the sense of precession is reversed so that the charge moves in the direction of divergence, the mass is progressively removed through that port into an adjoining discharge duct.

By extension, this principle is also applicable to vessels wherein a charge is set in motion, with a definite circular component of displacement, by agitator means other than the aforedescribed wobble drive.

According to a further feature of our invention, the discharge duct may include a perforated section or screen for the separation of a smaller-size fraction from the remainder of the outgoing charge. Either this fraction or the remainder can then be channeled back to the treatment chamber, the other fraction being removed from the system.

Advantageously, the discharge duct rises from the output port to a level above the chamber so that the charge may not leave the vessel during possible interruptions of the agitator motion. With the screening section located at or near the highest point of the discharge duct, the return channel may slope continuously downwardly toward an inlet port of the treatment chamber which may coincide with the outlet port or which also enters that chamber tangentially but with an orientation opposite that of the outlet port.

The above and other features of our invention will be described in greater detail hereinafter with reference to the accompanying drawing in which:

FIG. 1 is a somewhat diagrammatic top plan view of an upwardly open tumbling vessel according to the invention:

FIGS. 26 are views similar to FIG. 1, illustrating various modifications;

FIG. 7 is a side-elevational view of the apparatus shown in FIG. 6;

FIG. 7a is an elevational view of a modification of the upper part of the apparatus of FIG. 7;

FIG. 8 is a top plan view, partly in section, of another tumbling machine with two vessels according to the invention;

FIG. 9 is an elevational view of the machine of FIG. 8: and

FIG. 10 is a somewhat dia rammatic perspective view of another tumbling vessel with an associated wobble drive.

Throughout the drawing, upwardly and downwardly sloping ducts have been conveniently indicated by chevrons whose vertices point in the ascending direction and whose spacing varies inversely with the slope.

In FIG. 1 we have shown an upwardly open vessel 1 forming an annular treatment chamber 11 bounded by an inner wall 2 and a outer wall 12. The outer wall has an outlet port 8 branching substantially tangentially off the chamber 11 and leading to an upwardly sloping discharge duct 5. The vessel 1 is resiliently supported on a stationary base, in a manner illustrated in succeeding figures, and is set in wobbling motion by an impeller shaft 3 unbalanced by a lower weight 4 and an upper weight 4 positioned 90 apart. The driving connection between shaft 3 and vessel 1 will be discussed hereinafter in greater detail with reference to FIG. 10.

Shaft 3 is connected to a reversible drive motor, not shown here, so as to be rotatable clockwise or counterclockwise. The counterclockwise rotation will be considered the operating direction whereas the clockwise rotation represents the discharging direction. Weights 4 and 4' are so positioned that the upper weight 4' leads the lower weight 4 in the operating direction.

During operation, a charge in chamber 11 circulates counterclockwise as indicated by a solid arrow Its particles move. therefore, past the outlet port 8 without ever leaving the chamber. When, however, the sense of rotation is reversed, the constituents of the charge are moved toward port 8 in the direction indicated by a broken arrow E and exit via duct 5 as shown by another broken arrow E. Upon such reversal of motion, weight 4 is displaced by 180 with reference to weight 4 to preserve its leading phase angle.

FIG. 2 shows a generally similar vessel 1a with a treatment chamber 11a having a sharp corner at 6, the tumbling action being intensified at that point. An outlet port 8a opens into the chamber bottom at a location remote from point 6, again in a substantially tangential direction, and leads to a discharge duct 5a rising from that port to an elevated level.

The vessel 1b illustrated in FIG. 3 is of rhombic outline and has two sharp inversion points 9, 10 for intensive treatments. A lateral outlet port 8b, leading to a discharge duct 5b, is disposed between these two inversion points.

In FIG. 4 we have shown a vessel 1c of triangular configuration. A lateral outlet port 80 branches off the center of one of its sides to give access to a discharge duct 50.

Naturally, the operation of each of these systems is analogous to that of FIG. 1.

In FIG. 5 there is shown a vessel 17 of similar triangular outline with an outlet port 18 leading to a discharge duct 13. An elevated section 14 of this duct has a perforated bottom through which a small-size fraction of the mass discharged from the vessel (arrow B) is delivered to an underlying chute 15 for removal from the system (arrow E). The remaining larger-size fraction is returned (arrow R) by a descending channel 16 to the vicinity of port 18 along the upwardly sloping stretch of duct 13. When the drive 3, 4, 4' resumes its forward rotation (arrow B), the particles deposited at the entrance of duct 13 are entrained back into the vesel 17 for recirculation.

In FIGS. 6 and 7 we show a similar vessel 20 with an outlet port 23 leading to a discharge duct 22 whi h terminates in a downward extension 25, a screen 24 being interposed between this duct and its extension. Below the screen 24 we provide a trough 26 whence a return channel 27 leads back to the vessel 20, terminating in the vlclnlty f port 23 in the general manner described with reference to FIG. 5. Thus, the larger parts T (e.g. wooden or metallic turnings) exit from the tail end of duct 22 and are dumped into a receptacle 30 whereas the smaller particles ,(e.g. abrasive chips) are fed back to the vessel. To accelerate their return, an opening 34 at the bottom of trough 26 leads directly to the underlying treatment chamber.

FIG. 7a illustrates an inversion of the arrangement of FIGS. 6 and 7, with an extension 31 of discharge duct 22 leading from screen section 24 back to the vessel to 4 feed back the large parts T while the small parts 1 are caught by a trough 32 underneath the screen 24 and are discharged from the system through a downwardly sloping outlet 33.

Naturally, the aforedescribed discharge and return operations occur only during reverse rotation as represented by arrows E and E.

The vessel 20 is shown supported in FIG. 7 on a nonrotatable platform 56 which is carried on a base 29 by means of coil springs 28 so as to swing radially outwardly in any direction.

In FIGS. 8 and 9 we have shown another tumbling machine wherein two eccentrically positioned vessels 40, are driven by a centrally positioned wobbling mechanism. The latter comprises a drive motor 52 rigidly connected with an input shaft 51 which is coupled with an impeller shaft 41 through two cascaded universal joints 57, 58 and an intermediate shaft 51'. A central housing accommodates two vertically spaced bearings 53, 54 (see FIG. 10) and terminates in a cap 43 accommodating the upper weight 42' and its lost-motion coupling; the lower weight 42 is directly fixed to the impeller shaft 41. Vessels 40 and 40' rest on a common nonrotatable platform 56 supported by springs 28. Each of these vessel is provided with a central boss 45 defining with its peripheral wall an annular treatment chamber in which a charge moves helicoidally, in the same manner as in the aforedescribed vessels, with a precession in one direction or the other as indicated by solid arrows B and broken arrow E in FIG. 8.

Each vessel is provided with a respective discharge duct 46, 46 originating at an outlet port 57 which opens substantially tangentially into the annular treatment chamber thereof and then rises above the level of the vessel, terminating in a downwardly sloping extension 48, 48'. Between this extension and the duct proper there is provided a perforated section 47, 47' whence a return duct 49, 49' extends to the corresponding treatment chamber, sloping downwardly toward that chamber and entering it at an inlet port 58 which opens also approximately tangentially into that chamber but with an orientation opposite that of outlet port 57.

In the operation of the system of FIGS. 8 and .9, counterclockwise rotation of shafts 51, 51, 41 causes the charge in each vessel to move in the same counterclockwise sense about the boss 45 as indicated by the arrows B. The charge then passes the outlet port 57 without leaving the chamber whereas any particles arriving at inlet port 58 are immediately entrained along its circulating path.

After the necessary treatment time, motor 52 is reversed so that the charge begins to circulate in the opposite sense (arrow E). Since, however, any particle approaching the outlet port 57 is immediately discharged into channel 46, there is no return flow through the inner branch of the treatment chamber so that the mass present in that branch will also move toward port 57 as indicated by an arrow E". The outfiowing mass (arrow E) arrives at the screen 47 or 47 Where the smaller particles are sifted out and returned to the chamber via channel 49 or 49 whereas the remainder exits at the terminal portion 48 or 48. The returning fraction of smaller particle size may again consist, for example, of abrasive chips admixed with larger parts, such as beads, dowels or pins, to be polished or deburred.

The vessels 40, 40 have open tops 44, 44 through which they can be reloaded after the motor 52 has been arrested or restarted in the forward direction V.

FIG. 10 shows the impeller shaft 41 journaled in bearings 53, 54 linked with the inner wall of an annular vessel 55 through spiders 61, 62. With the upper weight 42' leading the lower weight 42 in the forward direction of rotation (arrow V), i.e. counterclockwise, the staggered thrusts delivered to the top and the bottom of the vessel impart to that vessel a circularly progressing forward tilt synchronized with a radial excursion to generate a composite wobbling motion. Thus, the relatively mobile particles in the annular treatment chamber of vessel 55 move helicoidally along a closed path, the turns of the helicoid being represented by arrows U while the precessional movement has been conventionally symbolized at F and F the latter movement, of course, is codirectional with shaft rotation V (forward) or G (reversed).

The displacement of the upper weight 42 into its alternate position 42" (dotted lines) may be brought about automatically, upon a reversal of the direction of shaft rotation, by the momentum of the weight itself which is free to swing on the shaft through an arc of 180, preferably against a frictional restraining force, as more fully described in the copending application identified above.

It should be noted that the level of the lower spider 61 passes substantially through the center of gravity of the lpaded vessel whereas the upper spider 62 lies near the level of the top of its treatment chamber. The shaft 41, d isplaceable with reference to shaft 51 (FIG. 9) with two degrees of freedom, acts independently upon the vessel on these two levels.

We claim:

'1. A tumbling machine comprising at least one vessel forming a treatment chamber for a charge of relatively mobile parts, said vessel being provided with an outlet port in a wall of said chamber opening substantially tangentially into the latter; a discharge duct for said parts communicating with said port; agitator means for imparting to said charge a circulating motion along said wall; and reversible drive means for operating said agitator means in a sense in which said circulating motion is in the direction of convergence of said port with said chamber, thereby entraining all said parts past said port, and for subsequently operating said agitator means in an opposite sense in which said circulating motion is in the direction of divergence of said port from said chamber whereby said charge is progressively channeled into said duct.

2. A machine as defined in claim 1 wherein said vessel is provided with resilient support means holding same against rotation, said agitator means comprising an eccentric member rotatable about a substantially vertical axis and bearing upon said vessel for wobbling same with a precession codirectional with the rotation of said member.

3. A machine as defined in claim 2 wherein said chamber is of generally annular configuration in a substantially horizontal plane.

4. A machine as defined in claim 2 wherein said member comprises a universally jointed, generally upright shaft."

5'. A machine as defined in claim 4 wherein said weight means comprises an upper weight and a lower weight, said upper weight being positionable to lead said lower weight by approximately in either direction of rotation.

6. A machine as defined in claim 4 wherein said shaft is positioned outside the circumference of said chamber.

7. A machine as defined in claim 1 wherein said duct rises from said port to a level above the top of said treatment chamber.

8. A machine as defined in claim 1 wherein said duct is provided with an elevated screen section for separating a relatively large fraction of said charge from a relatively small fraction thereof.

9. A machine as defined in claim 8, further comprising conduit means leading from said screen section to said vessel for returning one of said fractions to said chamber.

References Cited UNITED STATES PATENTS 3,429,560 2/1969 Huber 51-163 X 3,074,068 1/1963 Balz 51-163 X 3,550,326 12/1970 Robinson 5l163 HAROLD D. WHITEH'EAD, Primary Examiner US. Cl. X.R. 

